(19)
(11) EP 0 260 114 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
26.04.1989 Bulletin 1989/17

(43) Date of publication A2:
16.03.1988 Bulletin 1988/11

(21) Application number: 87307939.6

(22) Date of filing: 08.09.1987
(51) International Patent Classification (IPC)4: G11B 11/10
(84) Designated Contracting States:
DE FR GB IT NL

(30) Priority: 12.09.1986 JP 215089/86

(71) Applicant: CANON KABUSHIKI KAISHA
Tokyo (JP)

(72) Inventor:
  • Koyama, Osamu
    Kawasaki-shi Kanagawa-ken (JP)

(74) Representative: Beresford, Keith Denis Lewis et al
BERESFORD & Co. 2-5 Warwick Court High Holborn
London WC1R 5DJ
London WC1R 5DJ (GB)


(56) References cited: : 
   
       


    (54) Opto-magnetic signal reproducing apparatus for reading, by differential detection using a magneto-optical effect, information magnetically recorded on a record medium


    (57) There is disclosed an opto-magnetic signal reproducing apparatus comprising a light source unit (1 to 4) for applying a linearly polarized light beam to a record medium (5) having magnetically recorded information, a splitter (3, 6, 7, 9) for splitting the light beam modulated responding to the recorded information by a magneto-optic effect, into two light beams having different polarization directions from each other, and a reproduce device (8, 10) for differentially detecting the split light beams to reproduce the recorded information and wherein the splitter imparts a phase difference equal to an integer multiple of π to each of the split light beams.






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